Such a device is typically electrically conductively connected to a printed circuit board (PCB). For this purpose, a surface-mountable device, however, does not have any leads which project out of the housing of the device or protrude beyond the housing to be connected to the printed circuit board in accordance with the principle of through hole installation. Instead, a surface-mountable device has a plurality of solderable connection surfaces by means of which the device is soldered to the printed circuit board. For tins purpose, a corresponding arrangement of contacting surfaces is provided at the printed circuit board. The contacting surfaces are printed with a solder paste, for example by means of screen printing/stencil printing. After the mounting of the printed circuit board with a plurality of devices, they are soldered to the contacting surfaces of the printed circuit board in the so-called reflow process, It is alternatively also known first to adhesively bond the surface-mountable devices onto the printed circuit board and finally to solder them in the so-called wave bath or splash bath.
A particularly advantageous type of surface-mountable devices without leads has a plurality of solderable connection surfaces at its lower side (i.e. at the bottom side of the device), with at least one of the connection surfaces (typically each of the connection surfaces) being formed by a rectangular portion. The arrangement of the connection surfaces at the lower side of the device is naturally exactly defined so that a corresponding arrangement of contacting surfaces can be provided at the associated printed circuit board. Different variants of such arrangements of connection surfaces at the lower device side are in particular known from the standard MO-236 (Issue B, MAR07) of the standardization organization JEDEC (Joint Electron Devices Engineering Council, 2500 Wilson Blvd., Suite 220, Arlington, Va. 22201-3834, USA; www.jedec.org).
A particular advantage of devices made in this manner consists of their only taking up little space on the printed circuit board. A large placement density (number of devices per unit of area) thus results. However, a mounting of the printed circuit board with a large device density requires a high precision of the mounting process. No visual inspection is possible due to the arrangement of the connection surfaces at the lower side of the devices so that a check of the contacting has to be carried out, when required, by use of X-rays. This problem in particular relates to devices having a housing in accordance with an industrial standard according to which the respective connection surface at the lower side of the device should not extend directly up to a side edge of the lower device side, as is, for example, the case in the aforesaid JEDEC Standard MO-236.